Minor improvements to `ArcanistPhpLinter`
Minor improvements to `ArcanistPhpLinter`

Summary: Various minor improvements to `ArcanistPhpLinter`.

Test Plan: `arc unit`

Reviewers: epriestley, #blessed_reviewers

Reviewed By: epriestley, #blessed_reviewers

Subscribers: Korvin, epriestley

Differential Revision: https://secure.phabricator.com/D11265

KieranHayes/arcanist,alexmv/arcanist,memsql/arcanist,wikimedia/phabricator-arcanist,sneakpeeq/arcanist,Symplicity/arcanist,sneakpeeq/arcanist,alexmv/arcanist,codelabs-ch/arcanist,PageUpPeopleOrg/arcanist-patches,calblueprint/arcanist,Khan/arcanist,wxstars/arcanist,eSpark/arcanist,r4nt/arcanist,kevinseelbach/arcanist,wikimedia/phabricator-arcanist,uber/arcanist,aik099/arcanist,folsom-labs/arcanist,fivestars/arcanist,chundongwang/arcanist,chundongwang/arcanist,Khan/arcanist,coursera/arcanist,haskell-infra/arcanist,memsql/arcanist,r4nt/arcanist,Symplicity/arcanist,Symplicity/arcanist,PageUpPeopleOrg/arcanist-patches,codelabs-ch/arcanist,KieranHayes/arcanist,KieranHayes/arcanist,codelabs-ch/arcanist,uber/arcanist,coursera/arcanist,wharris/arcanist,wxstars/arcanist,jra3/arcanist,fivestars/arcanist,eSpark/arcanist,memsql/arcanist,uber/arcanist,wikimedia/phabricator-arcanist,calblueprint/arcanist,r4nt/arcanist,hach-que/arcanist,folsom-labs/arcanist,uber/arcanist,jra3/arcanist,wharris/arcanist,haskell-infra/arcanist,calblueprint/arcanist,haskell-infra/arcanist,sneakpeeq/arcanist,fivestars/arcanist,wikimedia/phabricator-arcanist,eSpark/arcanist,folsom-labs/arcanist,hach-que/arcanist,Khan/arcanist,calblueprint/arcanist,codelabs-ch/arcanist,r4nt/arcanist,KieranHayes/arcanist,phacility/arcanist,chundongwang/arcanist,PageUpPeopleOrg/arcanist-patches,kevinseelbach/arcanist,Khan/arcanist,jra3/arcanist,wharris/arcanist,zhihu/arcanist,phacility/arcanist,phacility/arcanist,PageUpPeopleOrg/arcanist-patches,zhihu/arcanist,eSpark/arcanist,kevinseelbach/arcanist,hach-que/arcanist,fivestars/arcanist,phacility/arcanist,zhihu/arcanist,hach-que/arcanist,wxstars/arcanist,haskell-infra/arcanist,wharris/arcanist,alexmv/arcanist,jra3/arcanist,coursera/arcanist,sneakpeeq/arcanist,Symplicity/arcanist,alexmv/arcanist,coursera/arcanist,aik099/arcanist,chundongwang/arcanist,phacility/arcanist,zhihu/arcanist,aik099/arcanist,kevinseelbach/arcanist,codelabs-ch/arcanist,aik099/arcanist,folsom-labs/arcanist,wxstars/arcanist,memsql/arcanist